Newton's contribution to physics: MCQ with Answer and Explanation

Explanation:
Recombination of electrons and holes emits light in forward-biased p-n junction.

Explanation:
g = 4π²l/T² ⇒ %Δg = %Δl + 2×%ΔT. Assuming l precise: %Δg ≈ 2×(0.1/2.0×100%) = 2×5% = 10%. Memory tip: 'g ∝ 1/T² ⇒ %Δg = 2×%ΔT'. Error analysis frequently tested in competitive experimental physics sections.

Explanation:
Newton's third law states that to every action, there is an equal and opposite reaction. Crucially, action and reaction forces always act on two different bodies. Because they act on different bodies, they do not cancel each other out, and each body experiences a net force based on the reaction it receives.